It is in our nature, as men, to love all kinds of achievements and competitions that would bring us recognition. Choosing a new target every day, setting a new goal for the next, it all breeds satisfaction and helps us overcome feelings of inadequacy. It strengthens our sense of self and our identity. It is this constant pursuit that gives meaning to a man's life, driving abundance and happiness along the way. Then, when a man becomes a father, he enters a new stage of life with the inescapable excitement of an athlete competing for the first time in the Olympics. Completely unaware that no other competition throughout his entire life will test his limits more than this one, he steps into the arena not knowing that this ultra-marathon will change him irreversibly, in so many and unexpected ways. The once “Iron Man” will gradually “melt” beyond his imagination, but once the process starts, he will feel increasingly ashamed of his old self and more in love with his new vision and his new life. We hereby invite you to sit back, relax, and allow yourself to be captivated by this collection of insights, scientific findings, sound logical inferences, and powerful stories. Let it fulfill our audacious mission of rediscovering the meaning of fatherhood!